A clutch cover assembly having long life and a diaphragm spring is required for taxis, business car and the like.
As an example of long-life, it is known that the life of a clutch is increased by fastening the facing to the clutch disc without rivets.
A conventional clutch cover assembly is shown in FIG. 5. A wear-in of the facing, in the facing used part D is established by a load characteristic as shown in FIG. 6. Since the wear-in D has a limit, an incline of the diaphragm spring, at clutch engagement, increases according to the increase of wear. Thus, the characteristic load is transformed and it is not possible to use the facing to the maximum quantity of wear. Especially in a twin type clutch, it is more difficult than in a single type clutch to get a long-life because the twin type clutch require double clearances compared to the single type clutch.
An object of this invention is to maintain initial set load even at the time of wear of the facings, and get a long-lived clutch without transforming pressure load.